Coppice abandonment had negative consequences for the biodiversity of forest vegetation and several groups of invertebrates. Most coppicing restoration studies have focused only on a single trophic level despite the fact that ecosystems are characterized by interactions between trophic levels represented by various groups of organisms. To address the patterns of functional diversity in the perspective of coppicing restoration, we studied the short-term effects of conservation-motivated tree canopy thinning in an abandoned coppice with standards in Central Europe, a region where such attempts have been rare so far. The functional diversity of vascular plants and spiders, chosen as two model trophic groups within the forest ecosystem, was compared between thinned and control forest patches. To characterize functional patterns, we examined several functional traits. These traits were assigned to two contrasting categories: response traits reflecting a change of environment (for both vascular plants and spiders) and effect traits influencing the ecosystem properties (only for vascular plants). Functional diversity was analysed by CCA using two measures: community-weighted means (CWM) and Rao’s quadratic diversity (RaoQ). CCA models revealed that the canopy thinning had a positive effect on the diversity of the response traits of both trophic groups and negatively influenced the diversity of effect traits. In addition, we found distinct seasonal dynamics in functional diversity of the spider communities, which was probably linked to leaf phenology of deciduous trees. We conclude that canopy thinning affected functional diversity across trophic groups during the initial phase of coppicing restoration. With necessary precautions, careful canopy thinning can be effectively applied in the restoration of functional diversity in abandoned coppices.

中文翻译：

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废弃林中树冠稀疏后两个营养群的功能多样性模式

废弃林地对森林植被和一些无脊椎动物的生物多样性产生了负面影响。大多数矮林恢复研究只关注单一营养级，尽管生态系统的特点是不同生物体代表的营养级之间的相互作用。为了从灌木丛恢复的角度解决功能多样性的模式，我们研究了中欧标准的废弃灌木丛中以保护为动机的树冠稀疏的短期影响，迄今为止，此类尝试很少见。维管束植物和蜘蛛被选为森林生态系统中的两个模型营养类群，在间伐森林斑块和对照森林斑块之间进行了比较。为了表征功能模式，我们检查了几个功能特征。这些性状被分配到两个对比类别：反映环境变化的响应性状（对于维管植物和蜘蛛）和影响生态系统特性的效应性状（仅对于维管植物）。CCA 使用两种度量来分析功能多样性：群落加权平均值 (CWM) 和 Rao 二次多样性 (RaoQ)。CCA模型显示，冠层稀疏对两个营养群的响应性状多样性产生积极影响，并对效应性状多样性产生负面影响。此外，我们发现蜘蛛群落功能多样性具有明显的季节性动态，这可能与落叶乔木的叶子物候有关。我们得出的结论是，在矮林恢复的初始阶段，冠层稀疏影响了各个营养群体的功能多样性。通过采取必要的预防措施，仔细的树冠间伐可以有效地恢复废弃矮林的功能多样性。